Manufacture of substances precipitating glue



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ADOLF 0E STUTTG-ABT, GERMANY, ASSIGNOB, BY MESNE ASSIQNM T5, T0

ADOLF KUTTROFF, OF NEW YORK, N. Y.

MANUFACTURE OF SUBSTANCES I PBECIPITATING GLUE.

Specification of Letters Patent.

Patented Apr. 26, 192i.

Ito Drawing. Application filed November 28, 1914, Seria1 No. 874,540. Renewed April 24, 1920. Serial To all whom it may concern:

long time ozor 6-naphthol with a quantity I of concentrated sulfuric acid calculated for one molecule, or with a slight excess of sulfuric acid (to about 25%) to temperatures of over 100, it is possible to obtain new products of condensation of acid character,

' soluble in water, such products substantially differing from the well-known 1- or 2-oxynaphthalene sulfonic-acids obtained by the action of larger quantities of sulfuricacid on naphthalene, by the fact that they have considerable properties of precipitating glue, which is not the case in such degree with the ordinary sulfonic-acids. The heating as above described may also with advantage be carried outin the presence of a condensing agent such as phosphorus oxychlorid. Thus.

, the naphthol ma be heated at a mild temperature with p osphorus oxychlorid and a small quantity of sulfuric acid added during the heating.

The use of aand -naphthol as raw material for substances suitable for tanning, is combined with a considerable advantage, as the. slight tanning properties which naphthols already possess, become more favorably pronounced in the products of condensation. The said products strongly precipitate glue,

, and partly can precipitate glue from its solutions in completely neutral solution and even 'in the presenceof sodium carbonate, which has never been yet observed. Owing to these technically Valuable properties, the new substances can be used for tanning even in neutral or very slightly acid liquor. Such properties have never been known or utilized in any of the synthetic tanning substances hitherto known.

Example 1.

21 parts by weight of c or t-naphthol are stirred in 18 parts by weight of concentrated sulfuric acid. The composition produced is heated for 4 hours to about 120. If during heating a sample dissolved in water no longer shows any increase in the precipitation of glue, the mixture of composition is dissolved in water, boiled and eventually filtered. The slight quantities of excess of sulfuric acld are made to combine with lime. The clear solution filtered off from the sulfate of calcium, isconve1ted with carbonate of sodium into a salt of sodium and separated by filtering from the carbonate of lime precipitated. The acidified solution is distinguished by strongly tanning properties, and can be used direct for tanning. Both the ozand t-naphthol form during the abovedescribed heating, a dark mixture or compositlon which is easily soluble in water and can be precipitated again by concentrated hydrochloric acid.

The tanning is then carried out in the following manner:

The solution of the product of condensation from 5 kg. naphthol, manufactured in accordance with the example 1 and slightly acidified, is placed into 500 liters of water, and the hides or skins prepared in the usual manner are introduced into the solution in question. The liquor is gradually improved by the addition of concentrated solutions, until the desired degree of tanning has been taken from the first with considerably greater strength. F or instance. a solution of 2%% is taken first, and the proportion of tanning material is increased by further additions of concentrated solutions to about 4%, and the tanning is completed at the latter concentration.

It has' been further. found that the well known sulfonic acids of the aand t-oxynaphthalene are also converted into such products of condensation which precipitate glue, when they are heated, alone or with an addition of suitable condensing substances, such as for instance sulfuric acid, phosphorus oxy-chlorid or the like. The heating may be preferably eifected with the exclusion of air or in a vacuum, in order to avoid any oxidation.

Example 2.

22 parts by weight of l-oxyna hthalenel-sulfonic acid are mixed with 2- parts by weight of concentrated sulfuric acid and heated for several hours to 120. If a sample taken as described above, shows that the glue precipitation no longer increases, the mass obtained is dissolved in water and treated as above.

The product differs from the raw material, inaddition to the strong glue-precipltating property, by its considerably smaller fluorescence, and more particularly by the difference of the dyes which it forms by combining with diazo-compounds. The dyes obtained with the new product of condensation, become much more strongly red or blue, and behave in a completely different manner when treated with concentrated hydrochloric acid. For instance, the color of the well-known azo-dye obtained from diazo benzol and 1 oxynaphthalene 4 sulfonic-acid, turns much less to blue-red than that of the corresponding dye obtained from the new product of condensation.

E wample 3.

25 parts by 6-sulfonic-ac1d are mixed with, say, 25 parts by weight of oxy-chlorid of phosphorus, slowly heated in a water bath and then kept from one to two hours in a boiling water bath. \Vhen a sample no longer shows any increase in theprecipitation of glue, the mixture is introduced into water, and the product of condensation is either precipi tated direct by means of sodium chlorid, or purified by means of lime and sodium salt. In many cases, the raw mixture dissolved in water can also be used for tanning. The product of condensation thus obtained, produces a strong precipitation of glue in alkaline, neutral or acid solutions. Any excess of oxychlorid of phosphorus can be removed by distillation before dissolving the mixture in water.

While in the preceding example equal parts by weight of oxychlorid of phosphorus and of an oxy-naphthalene-sulfonic-acid were caused to act on each other at the-temperature of water bath, it has been found that products of condensation can be obtained, which are soluble with much greater difliculty, but have the same glue-precipitating property when the quantity of oxychlorid of phosphorus is increased and the temperature raised.

Example 4.

weight of 2-oxynaphthalene 1. A process of making tanning substances which comprises heating a naphtholsulfonic acid to effect the formation of a new product which is capable of strongly precipitating glue.

process of making tanning sub stances which comprises heating a naph thol-sulfonic acid in the absence of air to effect the formation of a'new product which is capable of strongly precipitating glue.

3. A process of making tanning substances which comprises heating a naphthol-sulfonic acid in a vacuum to efiect the formation of a new product which is capable of strongly precipitating glue.

process of making tanning substances which comprises heating a naphthol-sulfonic acid with a condensing agent to effect the formation of a new product wlhich is capable of strongly precipitating g ue. I 5. A process of making tanning sub stances which comprises heating a naphthol-sulfonic acid in a vacuum with a condensing agent to effect the formation of a new product which is capable of strongly precipitating glue.

process of making tanning substances which comprises heating a naph-,

thol-sulfonic acid with a small quantity of sulfuric acid to effect the formation of a new product which is capable of strongly precipitating glue.

7. A process of making tanning substances which comprises heating in a vacuum a naphthol sulfonic acid with a small quantity of sulfuric acid to effect the formation of a new product Which is capable of stron ly precipitating glue.

8. process of making tanning substances which comprises heating a na-phthol sulfonic acid with a small quantity of sulfuric acid and with phosphorus oxychlorid to effect the formation of a new product uihich is capable of strongly precipitating g ue.

9. A process of making tanning. substances which comprises heating a naphthol with about one molecular proportion of concentrated sulfuric acid to effect the formation of a new product which is capable of strongly precipitating glue.

,10. A process of making tanning substances which comprises heating a naphthol with about one molecular proportion of concentrated sulfuric acid and with phosphorus-oxychlorid to effect the formationiof a new product which is capable of strongly precipitating glue.

11. A process of making tanning substances which comprises heating in a vacuum a naphthol with about one molecular equivalent of concentrated sulfuric acid to effect the formation of a new product which is capable of strongly precipitating glue.

12. A process of making tanning substances which comprises heating in a vacuum a naphthol with about one molecular equivalent of concentrated sulfuric acid and with phosphorus-oxychlorid to efi'ect the for &

mation of a new product which is capable of strongly precipitating glue.

13. As a new composition of matter a condensation product of a naphthol sulfonic acid which product has strong glue-precipitating properties and is obtainable by heating a sulfonated naphthol at about 120 degrees centigrade, the new product containing at least two naphthalene nuclei in its molecule.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

DR'ADOLF RoMnR.

Witnesses:

FREDA K. CRIBER, PAULINE Mr'iLLnR. 

